Laser survey of rail network helps client to procure new locomotives for bauxite mine
Rio Tinto, Weipa Australia

Business Challenge
Rio Tinto Alcan operates a bauxite mine located in Weipa, on the western side of Cape York Peninsula in far north Queensland. The mine has a dedicated 18 km rail network that is used to haul bauxite from the Andoom mine site to the mine's port on the Embley River for shipment to domestic and overseas markets.

Rio Tinto Alcan had predicted increased demand for bauxite and, in order to meet increased haulage tonnages, had ordered two new locomotives. To ensure a fit for purpose design of these locomotives, Rio Tinto Alcan had two requirements:

• Ensure in advance that the new locomotives would successfully pass through all existing rail infrastructure and meet all clearance requirements.
• Define a maximum clearance profile for the network. This would allow Rio Tinto Alcan to maximise the width of the locomotive fuel tanks and thus reduce the frequency of refuelling.

Services Overview
Geomatic Technologies (GT) undertook a laser clearance survey of the rail network using its Asset Inspection and Mapping System (AIMS). AIMS facilitates the capture of 360 degree laser profiles at a frequency of 75 times per second.

By using a structure gauge template of the locomotive, and "pushing" this through the laser point cloud data, encroachments were defined through kinematic analysis based on vehicle dynamics (body roll etc) and track curvature.

Encroachments found were categorised according to their location kilometrage and type (bridge, signal, vegetation, etc). The final deliverable to the client comprised of a spatial dataset of laser data images at each encroachment location.

A secondary requirement of the project was to map all track centrelines on the network using AIMS. The deliverable to the client comprised of a spatial database of all track centrelines on the network that included kilometrage information at 1 metre intervals and curve radius information.

Finally, by analysing the entire set of laser data collected during the survey, a maximum clearance profile was produced for the Rio Tinto Alcan rail network.

Outcomes

• Rio Tinto Alcan was confident that the new locomotives would pass successfully through the rail network without any structure gauge encroachments.
• Rio Tinto Alcan could define the maximum allowable width for fuel tanks to minimise the frequency of refuelling and achieve the associated cost savings and productivity increases.
• Rio Tinto Alcan now had an accurate and up-to-date track centreline.

Images above from left to right
Bauxite train wagons at Andoom mine, Weipa. Part of the Rio Tinto train infrastructure. A product stacker piles processed bauxite into stockpiles at Lorim Point, Weipa. Images courtesy Rio Tinto.